1. Field of the Invention
The invention relates in general to insertion machines for bulk assembly of mail pieces, and in particular to a system for sealing envelopes as they are transported along a conveyor.
2. Related Art
Sealers have been known for use in mail-processing machines, such as insertion machines, for wetting and sealing an envelope flap after the envelope has been stuffed with inserts by upstream insertion stations. Sealers of the prior art have generally included flap-wetting systems which operate to apply an inconsistent and/or imprecise amount of water to the flaps of envelopes travelling therethrough, resulting in such undesireable effects as over-wetting of the flap, which may cause the flap to curl and become jammed in the machine transport, and under-wetting of the flap, which may cause unintentional non-sealing of the flap. If, for example, the machine as a whole slows from a surface transport speed of 75 inches-per-second to 25 inches-per-second, undesireable results, such as over-wetting of an envelope, may occur.
Sealers and insertion stations have often been made integral in a single machine, such that the sealer relies on machine-wide resources such as transport motors, timing mechanisms, transport mechanisms, power supplies, etc. However, this integration yields a sealer which does not operate independently, resulting in inconsistent sealing operations.